Recovery-oriented care is an imperative for the VA, particularly in mental health programming for Veterans with serious mental illness (SMI). Collaborative decision-making (CDM) is a recovery-oriented approach to treatment decision-making that assigns equal participation and obligation to patients and providers across all aspects of decision-making, thereby empowering patients and facilitating better decision-making based on patient values and preferences. CDM is associated with several important outcomes including improved treatment engagement, treatment satisfaction, and social functioning. However, current levels of CDM among Veterans with SMI are low, and there is not yet an evidence-based method to improve CDM. Improving Veteran skill sets associated with engaging in CDM is a potential intervention strategy. Collaborative Decision Skills Training (CDST) is a promising new intervention that was previously developed by the applicant for use in adult civilians with SMI and found to improve relevant skills and improve sense of personal recovery. The proposed study has two primary stages. First, a small, one-armed, open label trial will establish CDST's feasibility will evaluate CDST among 12 Veterans with SMI receiving services at the VA San Diego Psychosocial Rehabilitation and Recovery Center (PRRC) and identify and complete any needed adaptations to CDST. Stakeholder feedback from Veterans, VA clinicians, and VA administrators will be collected to assess Veteran needs and service context to identify any needed adaptations to the CDST manual or the delivery of CDST to maximize its impact and feasibility. The developers of CDST (the applicant and Dr. William Spaulding, a consultant) will review all feedback and make final decisions about adaptations to ensure that CDST retains its essential components to protect against loss of efficacy. For example, a recommendation to adjust role-play topics to better reflect the needs of Veterans would be accepted because it would increase CDST's relevance without impairing its integrity, but a recommendation to remove all role-plays would not be accepted because it would cause loss of a key component. Second, CDST will be compared to active control (AC) using a randomized clinical trial of 72 Veterans. The primary outcome measure will be functioning within the rehabilitation context, operationalized as frequency of Veteran CDM behaviors during Veteran-provider interactions. Secondary outcomes are treatment attendance, engagement, satisfaction, and motivation, along with treatment outcomes (i.e., rehabilitation goal attainment, sense of personal recovery, symptom severity, and social functioning). Three exploratory outcomes will be assessed: Veteran-initiated collaborative behaviors, acute service use and provider attitudes and behavior. Veterans will be randomly assigned to CDST or AC conditions. Veterans in the both groups will attend eight hour-long group sessions held over eight weeks. All Veterans will complete an assessment battery at baseline, post-intervention, and at three-month post-intervention follow-up. Following the trial and adaptation phase, the findings will be used to develop a CDST service delivery manual and design a logical subsequent study. The results of the proposed study will inform the potential for larger trials of CDST and the utility of providing CDST broadly to Veterans with SMI. The results of this study will expand current understanding of CDM among Veterans with SMI by providing data that will: 1) identify adaptations needed to optimize CDST for Veterans receiving services in PRRCs; 2) identify possible benefits of CDST; 3) inform development of alternate interventions or methods to improve CDM; and 4) further elucidate CDM and associated treatment processes among Veterans with SMI receiving VA rehabilitation services.